{"id":797248,"date":"2025-07-13T03:53:06","date_gmt":"2025-07-13T08:53:06","guid":{"rendered":"https:\/\/spaceweekly.com\/?p=797248"},"modified":"2025-07-13T03:53:06","modified_gmt":"2025-07-13T08:53:06","slug":"today-in-2015-new-horizons-at-pluto","status":"publish","type":"post","link":"https:\/\/spaceweekly.com\/?p=797248","title":{"rendered":"Today in 2015: New Horizons at Pluto"},"content":{"rendered":"<p> <br \/>\n<\/p>\n<div>\n<figure id=\"attachment_387761\" aria-describedby=\"caption-attachment-387761\" style=\"width: 800px\" class=\"wp-caption alignnone\"><figcaption id=\"caption-attachment-387761\" class=\"wp-caption-text\">View larger. | When New Horizons arrived at Pluto in 2015, it found this large heart-shaped feature on the planet\u2019s surface. Pluto\u2019s \u201cheart\u201d measures approximately 1,000 miles (1,600 km) across. It\u2019s a vast plain of nitrogen ice. Image via NASA\/ JHUAPL\/ SwRI\/ The University of Arizona.<\/figcaption><\/figure>\n<h3>July 14, 2015: New Horizons at Pluto<\/h3>\n<p>Ten years ago tomorrow, NASA\u2019s New Horizons spacecraft passed distant Pluto, sweeping only about 7,750 miles (12,472 km) above its surface. The fast-moving spacecraft had traveled almost 10 years and three billion miles (five billion km) to reach Pluto. The journey took only about a minute less than what the mission team predicted when the craft launched in January 2006. Once at Pluto, New Horizons \u201cthreaded a needle\u201d through a 36-by-57 miles (58 by 92 km) window in space. Comparatively, that\u2019s like a commercial airliner arriving no more off target than the width of a tennis ball.<\/p>\n<p>In addition, New Horizons was the first-ever space mission to view Pluto and its moons (Charon, Nix, Hydra, Styx and Kerberos) up close. <\/p>\n<p>It\u2019ll likely be the only space mission to Pluto in the lifetimes of many of us. <\/p>\n<h3>Surprising and amazing<\/h3>\n<p>A year after the New Horizons flyby, the mission\u2019s principal investigator Alan Stern of the Southwest Research Institute, Boulder, Colorado, listed the mission\u2019s most surprising and amazing findings:<\/p>\n<blockquote>\n<ul>\n<li>The complexity of Pluto and its satellites is far beyond what we expected.<\/li>\n<li>The degree of current activity on Pluto\u2019s surface and the youth of some surfaces on Pluto is simply astounding.<\/li>\n<li>Pluto\u2019s atmospheric hazes and lower-than-predicted atmospheric escape rate upends all of the pre-flyby models.<\/li>\n<li>Charon\u2019s enormous equatorial extensional tectonic belt hints at the freezing of a former water ice ocean inside Charon in the distant past. Other evidence from New Horizons indicates Pluto could well have an internal water-ice ocean today.<\/li>\n<li>All of Pluto\u2019s moons that can be age-dated by surface craters have the same, ancient age, adding weight to the theory that they were formed together in a single collision between Pluto and another planet in the Kuiper Belt long ago.<\/li>\n<li>Charon\u2019s dark red polar cap is unprecedented in the solar system and may be the result of atmospheric gases that escaped Pluto and then accreted on Charon\u2019s surface.<\/li>\n<li>Pluto\u2019s vast 1,000-kilometers-wide (621-miles-wide) heart-shaped nitrogen glacier (informally called Sputnik Planitia) that New Horizons discovered is the largest known glacier in the solar system.<\/li>\n<li>Pluto shows evidence of vast changes in atmospheric pressure and, possibly, past presence of running or standing liquid volatiles on its surface; something only seen elsewhere on Earth, Mars and Saturn\u2019s moon Titan in our solar system.<\/li>\n<li>The lack of additional Pluto satellites beyond what was discovered before New Horizons was unexpected.<\/li>\n<li>Pluto\u2019s atmosphere is blue. Who knew?<\/li>\n<\/ul>\n<\/blockquote>\n<h3>Watching from mission control<\/h3>\n<figure id=\"attachment_398391\" aria-describedby=\"caption-attachment-398391\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/earthsky.org\/upl\/2022\/07\/NASA-new-horizons-team.jpg\" alt=\"New Horizons: 3 people laughing and looking at out-of-sight screen.\" width=\"800\" height=\"540\" class=\"size-full wp-image-398391\" srcset=\"https:\/\/earthsky.org\/upl\/2022\/07\/NASA-new-horizons-team.jpg 800w, https:\/\/earthsky.org\/upl\/2022\/07\/NASA-new-horizons-team-300x203.jpg 300w, https:\/\/earthsky.org\/upl\/2022\/07\/NASA-new-horizons-team-768x518.jpg 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\"\/><figcaption id=\"caption-attachment-398391\" class=\"wp-caption-text\">New Horizons team members react with joy and amazement. This is the NASA New Horizons Pluto Flyby team viewing the last image before the flyby of Pluto. Image via NASA.<\/figcaption><\/figure>\n<figure id=\"attachment_223246\" aria-describedby=\"caption-attachment-223246\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/earthsky.org\/upl\/2015\/07\/new-horizons-science-team-july-10-2105-e1436722756645.jpg\" alt=\"New Horizons: 6 scientists looking at a computer screen react with amazement to the latest image of Pluto.\" width=\"800\" height=\"794\" class=\"size-full wp-image-223246\"\/><figcaption id=\"caption-attachment-223246\" class=\"wp-caption-text\">Science team members react to the latest image of Pluto at the Johns Hopkins University Applied Physics Lab on July 10, 2015. Left to right: Cathy Olkin, Jason Cook, Alan Stern, Will Grundy, Casey Lisse and Carly Howett. Image via Michael Soluri.<\/figcaption><\/figure>\n<blockquote class=\"twitter-tweet\" lang=\"en\">\n<p lang=\"en\" dir=\"ltr\">LOCKED! We have confirmation of a successful <a rel=\"nofollow\" href=\"https:\/\/twitter.com\/hashtag\/PlutoFlyby?src=hash\">#PlutoFlyby<\/a>. <a rel=\"nofollow\" href=\"https:\/\/t.co\/Krfo9qxxHw\">pic.twitter.com\/Krfo9qxxHw<\/a><\/p>\n<p>\u2014 NASA New Horizons (@NASANewHorizons) <a rel=\"nofollow\" href=\"https:\/\/twitter.com\/NASANewHorizons\/status\/621120974667259904\">July 15, 2015<\/a><\/p>\n<\/blockquote>\n<h3>Pluto\u2019s heart<\/h3>\n<p>Among New Horizons\u2019 most immediate, stunning and visible findings was a bright heart-shaped feature on Pluto. Scientists named it Tombaugh Regio after Clyde Tombaugh. Its nickname is simply <em>The Heart<\/em>. <\/p>\n<figure id=\"attachment_223420\" aria-describedby=\"caption-attachment-223420\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/earthsky.org\/upl\/2015\/07\/Hubble-New-Horizons-comparison-Pluto.jpg\" alt=\"New Horizons: On the left, a blurry round ball, on the right a much-crisper image of Pluto with its heart-shaped feature.\" width=\"800\" height=\"354\" class=\"size-full wp-image-223420\"\/><figcaption id=\"caption-attachment-223420\" class=\"wp-caption-text\">Best image of Pluto from Hubble Space Telescope (left) in contrast to a New Horizons image of Pluto (right). Scientists knew there was a large bright spot on Pluto, but it took a spacecraft flyby to reveal that bright spot was Pluto\u2019s iconic Heart.<\/figcaption><\/figure>\n<h3>Ice mountains on Pluto<\/h3>\n<p>Another stunning discovery by New Horizons was finding ice mountains on Pluto, with peaks jutting as high as 11,000 feet (3,500 meters) above Pluto\u2019s surface. The mountains lie along Pluto\u2019s equatorial region near the base of The Heart. Scientists think that these mountains likely formed no more than 100 million years ago, making them extremely young in contrast to the 4.6-billion-year age of our solar system. Jeff Moore, a New Horizons imaging team member, said:<\/p>\n<blockquote>\n<p>This is one of the youngest surfaces we\u2019ve ever seen in the solar system.<\/p>\n<\/blockquote>\n<h3>Is Pluto geologically active?<\/h3>\n<p>In fact, on March 29, 2022, scientists announced that giant ice volcanoes create some of Pluto\u2019s most unusual surface features. Evidence suggests this is from recent activity, geologically speaking. Plus the ice volcanoes may still be erupting today.<\/p>\n<p>Read more about mountains on Pluto<\/p>\n<figure id=\"attachment_317077\" aria-describedby=\"caption-attachment-317077\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/earthsky.org\/upl\/2019\/07\/pluto-mountains-new-horizons-e1563050022624.png\" alt=\"New Horizons: Raised, elongated mountains on right side of orbital image of Pluto.\" width=\"800\" height=\"570\" class=\"size-full wp-image-317077\"\/><figcaption id=\"caption-attachment-317077\" class=\"wp-caption-text\">New Horizons images of a region near Pluto\u2019s equator reveal a range of young mountains rising as high as 11,000 feet (3,400 meters) above the surface. Scientists base this youthful age estimate on the lack of craters in the image above. Like the rest of Pluto, space debris pummeled this region for billions of years. And would have once been heavily cratered, unless recent activity gave the region a facelift, erasing those pockmarks. Image via NASA\/ JHUAPL\/ SwRI.<\/figcaption><\/figure>\n<h3>Looking back<\/h3>\n<p>A year after New Horizons\u2019 Pluto flyby, Hal Weaver, New Horizons project scientist from the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, said:<\/p>\n<blockquote>\n<p>It\u2019s strange to think that only a year ago, we still had no real idea of what the Pluto system was like. But it didn\u2019t take long for us to realize Pluto was something special, and like nothing we ever could have expected. We\u2019ve been astounded by the beauty and complexity of Pluto and its moons and we\u2019re excited about the discoveries still to come.<\/p>\n<\/blockquote>\n<p>If you ask these scientists today \u2013 years after the flyby \u2013 they\u2019d express a lot of the same excitement.<\/p>\n<figure id=\"attachment_317083\" aria-describedby=\"caption-attachment-317083\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/earthsky.org\/upl\/2019\/07\/pluto-backlit-atmosphere-new-horizons-e1563053363447.png\" alt=\"New Horizons: An illuminated edge of Pluto, backlit so that you can see its atmosphere.\" width=\"800\" height=\"341\" class=\"size-full wp-image-317083\"\/><figcaption id=\"caption-attachment-317083\" class=\"wp-caption-text\">New Horizons captured this image 15 minutes after its closest approach to Pluto on July 14, 2015, looking back toward the sun. The image is from a distance of 11,000 miles (17,700 km) to Pluto; the scene is 780 miles (1,255 km) wide. The back-lighting highlights over a dozen layers of haze in Pluto\u2019s tenuous but distended atmosphere. You can see Pluto\u2019s rugged, icy mountains and the flat ice plains extending to Pluto\u2019s horizon. Image via NASA\/ JHUAPL\/ SwRI.<\/figcaption><\/figure>\n<h3>Where is New Horizons now?<\/h3>\n<p>In early 2019, New Horizons encountered a second Kuiper Belt object, officially known as 2014 MU69 and previously nicknamed Ultima Thule. It has since been renamed to Arrokoth. Read more about the Arrokoth\/Ultima Thule encounter here. <\/p>\n<p>And in 2024, it was announced that New Horizons had discovered a second Kuiper Belt. <\/p>\n<p>Plus, in 2024, New Horizons was far enough out in our solar system to measure the light of the distant universe.<\/p>\n<p>And on June 30, 2025, NASA announced New Horizons performed the first interstellar navigation. That\u2019s because it is so far from Earth, the relative position of stars has shifted.<\/p>\n<p>New Horizon\u2019s mission to explore the solar system has been extended through 2029. It might perform more flybys of additional Kuiper Belt Objects (KBOs) in the late 2020s or 2030s. Stay tuned.<\/p>\n<p>So New Horizons is still out there \u2013 still within our solar system \u2013 speeding outward. <\/p>\n<p><iframe loading=\"lazy\" title=\"New Horizon&#039;s Speed\" width=\"1110\" height=\"624\" src=\"https:\/\/www.youtube.com\/embed\/8ywbQ5L7mQ0?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/p>\n<figure id=\"attachment_317087\" aria-describedby=\"caption-attachment-317087\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/earthsky.org\/upl\/2019\/07\/pluto-backlit-blue-skies-e1563054831859.png\" alt=\"New Horizons: Dark circular silhouette of backlit Pluto, surrounded by ring of blue haze.\" width=\"800\" height=\"800\" class=\"size-full wp-image-317087\"\/><figcaption id=\"caption-attachment-317087\" class=\"wp-caption-text\">The \u201cblue skies of Pluto\u201d from New Horizons after closest approach, with Pluto backlit by the sun. It is one of the most iconic images of the mission. Image via NASA\/ JHUAPL\/ SwRI.<\/figcaption><\/figure>\n<p>Bottom line: The New Horizons spacecraft flew past the Pluto system 10 years ago on July 14, 2015.<\/p>\n<p>Charon\u2019s red cap created by \u201catmospheric surges\u201d<\/p>\n<p>View all images of the Pluto encounter from New Horizons<\/p>\n<p>Enjoying EarthSky? Sign up for our free daily newsletter today!<\/p>\n<p><span class=\"cp-load-after-post\"\/><\/div>\n<div>\n<div class=\"post-author\">\n<h4>Deborah Byrd<\/h4>\n<p>                    View Articles\n                  <\/p><\/div>\n<div class=\"post-tags\">\n<h6 data-udy-fe=\"text_7c58270d\">About the Author:<\/h6>\n<p>Our Editor-in-Chief Deborah Byrd works to keep all the astronomy balls in the air between EarthSky&#8217;s website, YouTube page and social media platforms. She&#8217;s the primary editor of our popular daily newsletter and a frequent host of EarthSky livestreams. Deborah created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Prior to that, she had worked for the University of Texas McDonald Observatory since 1976, and created and produced their Star Date radio series. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. In 2020, she won the Education Prize from the American Astronomical Society, the largest organization of professional astronomers in North America. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. &#8220;Being an EarthSky editor is like hosting a big global party for cool nature-lovers,&#8221; she says.<\/p>\n<\/p><\/div>\n<\/p><\/div>\n<p><script async src=\"https:\/\/platform.twitter.com\/widgets.js\" charset=\"utf-8\"><\/script><br \/>\n<br \/><br \/>\n<br \/><a href=\"https:\/\/earthsky.org\/space\/july-4-2015-new-horizons-at-pluto\/?rand=772280\">Source link <\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>View larger. | When New Horizons arrived at Pluto in 2015, it found this large heart-shaped feature on the planet\u2019s surface. Pluto\u2019s \u201cheart\u201d measures approximately 1,000 miles (1,600 km) across.&hellip; <\/p>\n","protected":false},"author":1,"featured_media":797249,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[46],"tags":[],"class_list":["post-797248","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-earth-sky"],"_links":{"self":[{"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/posts\/797248","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=797248"}],"version-history":[{"count":0,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/posts\/797248\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/media\/797249"}],"wp:attachment":[{"href":"https:\/\/spaceweekly.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=797248"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=797248"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=797248"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}